Food Chains & Food Webs
Chapter 1.2-1.5
Food Chain
• Food chain:
– a relationship of organisms that depend on
each other for energy or food.
– Arrows point in direction of energy flow
• EX: algae is food for fish which are food
for squid which are food for sharks.
Food Web
• Food Web
– a group of
interrelated food
chains
Delicate Balance
• Diversity is key!
• Sometimes the removal of one species results in the
collapse of the ecosystem
– Ex: sea otter controls urchin population; if no sea otters,
urchins overgraze and collapse ecosystem